Antibody response to influenza, tetanus and pneumococcal vaccines in HIV-seropositive individuals in relation to the number of CD4+ lymphocytes.

OBJECTIVE

To establish when the formation of antibodies against T-lymphocyte-dependent and -independent antigens is impaired during HIV infection.

DESIGN

Prospective study on antibody formation before and 30 days and 60 days after vaccination with tetravalent influenza vaccine, tetanus toxoid and pneumococcal vaccine; booster with influenza vaccine was administered 30 days after initial vaccination.

SETTING

Outpatient clinic of University Hospital Leiden.

PARTICIPANTS

Fifty-one HIV-infected individuals and 10 healthy controls.

RESULTS

In HIV-infected individuals with < 100 x 10(6)/l CD4+ lymphocytes almost no influenza antibodies were formed; CD4+ counts between 100 and 300 x 10(6)/l correlated with suboptimal antibody formation; CD4+ counts > or = 300 x 10(6)/l yielded more individuals with protective antibody titres. Thirty days after vaccination, protective antibody titres against the four influenza strains had been achieved in 24% of all HIV-infected individuals for A/Beijing (H3N2) (controls, 90%), 59% for A/Taiwan (H1N1) (controls, 80%), 18% for B/Beijing (controls, 30%) and 37% for B/Panama (controls 90%). Booster vaccination after 1 month did not increase antibody levels. Anti-tetanus toxin antibody formation, which is also T-lymphocyte-dependent, was correlated with the number of CD4+ lymphocytes. After pneumococcal vaccination (T-lymphocyte-independent), normal antibody formation was observed in HIV-infected individuals, including those with low CD4+ counts.

CONCLUSIONS

Influenza vaccination should not be administered to HIV-infected individuals with CD4+ counts < 100 x 10(6)/l; pneumococcal vaccination can be offered to all HIV-infected individuals and a tetanus toxoid booster should be administered when indicated.